With my wheel aligned and spaced out, the anti rotate doesn't catch on the bung on the frame so I need to extend the bung. Eventually I may weld on an extension but right now I just plan to put in 2 bolts.

that's one way to do it, but it's easy to do with a caliper spacer in combination with your axle spacer(s). like this, then you caliper bracket has full engagement with the antirotation lug.